import java.util.List;

// 1、无头单向非循环链表实现
 public class SingleLinkedList {
    class ListNode {
        public int val;
        public ListNode next;

        public ListNode(int val) {
            this.val = val;
        }
    }
    public ListNode head;

    public void createList() {
        ListNode node1 = new ListNode(12);
        ListNode node2 = new ListNode(23);
        ListNode node3 = new ListNode(34);
        ListNode node4 = new ListNode(45);
        ListNode node5 = new ListNode(56);

        node1.next = node2;
        node2.next = node3;
        node3.next = node4;
        node4.next = node5;

        this.head = node1;
    }

    //遍历单链表
    public void display() {
        ListNode cur = head;
        while(cur != null) {
            System.out.print(cur.val + " ");
        }
        System.out.println();
    }
 }